The present invention relates to detection of a cooling abnormality in an electronic apparatus constituted by a heat-generating electronic part and having a means for cooling the part and, more particularly, to a temperature abnormality detecting system for detecting the temperature abnormality of a heat-generating element.
Today, due to the remarkable improvement of the performance of an electronic apparatus such as a computer, a heat generation density in an electronic apparatus is increasing. For this reason, various cooling methods such as a forced air cooling method and a liquid cooling method have been employed.
In an apparatus having such a cooling mechanism, the internal temperature is monitored by arranging a temperature sensor to protect the apparatus when an abnormality occurs in a cooling system.
A conventional temperature abnormality detecting system will be described below with reference to FIG. 4.
FIG. 4 shows a liquid cooling method. A heat-generating element 23 obtained by assembling integrated circuits and mounted in an electronic apparatus 21 is cooled by supplying a coolant such as water cooled by a cooling apparatus 22.
A current is supplied to the heat-generating element 23 by a power supply unit 25 through a line 211, the connection/disconnection of the power supply unit 25 is controlled by a control unit 26 through a line 212. In this case, a temperature sensor 24 is arranged on the heat-generating element 23, and the temperature is measured in the control unit 26 through a line 213. If the temperature reaches a predetermined temperature or more due to any abnormality in a cooling system, the control unit 26 detects this abnormality to disconnect the power supply unit 25 through the line 212, thereby protecting the heat-generating element 23.
FIG. 5 is a block diagram showing an arrangement of the control unit 26 shown in FIG. 4. FIG. 5 shows a section for controlling temperature measurement and a protecting process, and this section is constituted by a microprocessor 28 serving as its major component.
An output from an analog/digital (A/D) converter 27 receiving a signal at output signal level of the temperature sensor 24 through the line 213 is input to the microprocessor 28. When a temperature is detected as a predetermined temperature or more, an abnormality informing signal is output from an output unit A 30-1 to a host apparatus (not shown), and a power supply control signal is output from an output unit B 30-2 to the power supply unit 25 through the line 212. The microprocessor 28 is operated by a program written in a ROM 29 and controls temperature measurement, discrimination of a measurement value, and output of signals.
FIG. 6 is a flow chart showing an operation of the microprocessor 28 shown in FIG. 5. Predetermined processes are performed in steps S201 to S204, respectively.
The microprocessor 28 determines whether a temperature output from the A/D converter 27 is a predetermined temperature or more (step S202). If NO in step S202, measurement is repeated (step S201). When any failure of the cooling system occurs, and the temperature exceeds the predetermined temperature (step S202), a power-OFF signal is supplied to the power supply unit 25 (step S203) to disconnect the output of the power supply unit 25 and to inform a host apparatus of abnormality occurrence (step S204).
In this conventional temperature abnormality detecting system, when data representing a high temperature is detected due to a failure of a temperature sensor even though the temperature of a heat-generating element is normal, the control unit disadvantageously performs a power-OFF operation. In an apparatus such as a computer requiring a high reliability, the halt caused by such an erroneous detection poses a problem. In addition, in restoring after the halt, a long time is required for determining whether the temperature of the heat-generating element is actually high or the data representing a high temperature is detected due to the erroneous operation of a temperature sensor. Therefore, a long time is required for repairing the apparatus.